System for producing valves as for internal-combustion engines

ABSTRACT

A system is disclosed for use in the production of valves that include a disk or head which is integral with an axiallyextending shank or stem. As disclosed herein, a form or blank of such a valve initially is provided (as by various metal-forming techniques) with an annular groove at the peripheral edge of the head. The valve form is then placed in a chuck to provide electrical contact with substantially the entire periphery of the valve head thereby affording a locus of short paths for heat flow and an arc-welding electrical current. In accordance herewith, the valve is then rotated in relation to an arc-welding apparatus to accomplish an annulus of hard metal in the groove of the valve form. Finally, the valve form is finished by smoothing the deposited annulus to provide a seating surface that will matingly engage an engine port to accomplish closure.

United States Patent [1 1 Woods SYSTEM FOR PRODUCING VALVES AS FOR INTERNAL-COMBUSTION ENGINES [75] Inventor: Marion D. Woods, Whittier, Calif. [73] Assignee: Stoody Company, Whittier, Calif. [22] Filed: Oct. 6, 1972 [21] App], No.: 295,751

[52] 'U.S. Cl 219/76, 219/158, 219/161 [51] Int. Cl B23k 9/04 [58] Field of Search 219/76, 77, 158, 219/161, 136

[5 6] References Cited UNITED STATES PATENTS 1,606,181 11/1926 Rich 219/76 X 1,651,547 12/1927 Rich 219/76 2,043,773 6/1936 Rich 219/158 2,729,578 1/1956 Hedlund et al. 219/76 3,239,644 3/1966 Nyborg et a1 219/161 X CHUCK 02/ V6 'July 3, 1973 Primary Examiner-J. V. Truhe Attorney-Byard G. Nilsson et al.

[ 57] ABSTRACT A system is disclosed for use in the production of valves that include a disk or head which is integral with an axially-extending shank or stem. As disclosed herein, a form or blank of such a valve initially is provided (as by various metal-forming techniques) with an annular groove at the peripheral edge of the head The valve form is then placed in a chuck to provide electrical contact with substantially the entire periphery of the valve head thereby affording a locus of short paths for heat flow and an arc-welding electrical current. In accordance herewith, the valve is then rotated in relation to an arc-welding apparatus to accomplish an annulus of hard metal in the groove of the valve form. Finally, the valve form is finished by smoothing the deposited annulus to provide a seating surface that will matingly engage an engine port to accomplish closure.

10 Claims, 6 Drawing Figures CONTROL UN/T Patented July 3, 1973 2 Sheets-Sheet 2 9 6 W @w (6/ (0/ J2 SYSTEM FOR PRODUCING VALVES AS FOR INTERNAL-COMBUSTION ENGINES BACKGROUND AND SUMMARY OF THE INVENTION The performance of a conventional internalcombustion, automotive engine is significantly related to the effective operation of its valves. Generally, the operating rate of the valves is very high and occurs under adverse conditions. For example, the fuel and combustion products are somewhat destructive of the valve contact or seating surfaces in view of the operating rate and the adjacent temperatures. Current tendencies toward the use of pure fuels in internalcombustion engines compound the problem.

To prolong the effective life of the valves in an internal-combustion engine, it has been proposed to provide a casing of hard metal in an annular form at the location of the valve seat. The economy inherent to the application of hard metal by arc-welding techniques suggests such a method; however, several attendant problems have been encountered. Specifically, as the valves for automotive use are relatively small, arc-welding operations tend to produce elevated temperatures in substantial portions of the valves, which may adversely alter the characteristics of the deposited metal as by dilution. In an effort to maintain temperatures at a tolerable level, the hard metal has been applied to the periphery of the valve head with the flat surface of the head engaging a chill plate. Although production valves meet rather rigid specifications for certain dimensions, the flat surface of the head may vary substantially from a true plane. Further deviation results from thermal vshock unless heatis effectively controlled. Consequently, in efforts to employ the surface for electrically grounding thevalve, intimate contact has been difficult to maintain, resulting in spurious current paths that adversely affect the arc. Also, contact failures produce elevated temperatures in the valve. As a result, the technique of grounding the valve at its flat surface, as to a chill plate, has been found to result in rather unreliable production.

Another problem encountered in applying hard metal to the seating surface of a valve by arc-welding techniques, relates to impurities in the applied hard metal. To attain an improved standard, it is important to avoid any significant defects in the metal, as well as any demarcation at the termination or close of an annular deposit.

Generally, in accordance with the present system, the head of a valve is contacted so that the periphery is matingly engaged by a support chuck through which arc-welding grounding current may flow, along with heat from the arc-welding process. The chuck is revolved with reference to an arc-welding apparatus and the system is controlled so that on the completion of an BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, which constitute a part of this specification, exemplary embodiments exhibiting various objectives and features hereof are set forth, specifically:

FIG. 1 is a perspective and diagrammatic representation of a system incorporating the principles of the present invention;

FIG. 2 is a fragmentary vertical section of a component part of the system of FIG. 1;

FIG. 3 is a fragmentary horizontal section of a component part of the structure of FIG. 1;

FIG. 4 is a plan view of a valve constructed in accordance herewith;

FIG. 5 is a highly enlarged fragmentary and diagrammatic view of the structure of FIG. 4; and

FIG. 6 is a series of fragmentary sectional views illustrative of the production of the completed valve structure of FIG. 4.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT As required, a detailed illustrative embodiment of the invention is disclosed herein. The embodiment exemplifies the invention which may, of course, be embodied in other forms, some of which may be radically different from the illustrative embodiment as disclosed. However, the specific structural details disclosed herein are representative and they provide a basis for the claims which define the scope of the present invention.

Referring initially to FIG. 1, there is shown a valve V supported in a chuck apparatus C and receiving an annulus of hard metal applied by a welding apparatus W. Generally, the chuck apparatus C revolves in relation to the welding apparatus W to rotate the valve V through an angle that is somewhat greater than 360. During the rotation, the welding apparatus W deposits hard metal while the chuck apparatus C serves as a heat sink and establishes an effective pattern for electrical grounding currents. After the valve V has been rotated through 360, the size of the molten puddle is gradually reduced until the arc is finally extinguished.

Preliminary to considering the system of FIG. 1 in operative detail, some explanation in relation to the valve V will be provided with reference to FIGS. 4, 5 and 6. Valves for internal-combustion engines in the automotive field have become somewhat standardized, and include a valve head 10 (FIG. 4) in the form of a circular disk, with an integral stem 12 extending concentrically from the head. A tapered annular (truncated conical) seating surface 14 is defined at the periphery of the head 10 which comprises hard metal in accordance herewith and, of course, serves to engage a mating surface adjacent an engine port (not shown) in sealing relationship.

Generally, in the formation of a completed valve with the system hereof, a valve blank or form is preliminary provided defining an annular groove 16 (FIG. 6a). An annulus 18 (FIG. 6b) of hard metal is applied to the groove 16 which is subsequently finished by the removal of a fragment to define the smooth seating surface 14 (FIG. 6c).

In the production of valves, as suggested above, it is exceedingly important to maintain the annulus l8 uniform and substantially free of impurities. In that regard,

and in accordance herewith, theannulus 18 is deposited I in a specific pattern. That is, the metal is deposited in the groove 16 through one complete rotation of the valve (360 angle) after which the valve continues to be rotated; however, wire feed is halted and the arcing current is substantially reduced. As a consequence, a

re-heat pattern 22 as indicated in FIG. is provided whereby defects resulting from shrinkage as well as sharp discontinuities that might otherwise occur at a junction are substantially eliminated.

Reference will now be made to FIG. 1 for a detailed consideration of the system and its operation to accomplish a valve in accordance with the present invention. The chuck apparatus C is supported on a platform 24 (fragmentarily shown) which may comprise a part of a welding bench or a production machine. Mechanical connections from the chuck apparatus C are provided to a chuck actuating drive 26 and a rotary drive 28 as indicated by dashed lines 30 and 32, respectively. Functionally, the chuck actuating drive 26 opens and closes the chuck apparatus C while the rotary drive 28 revolves the chuck apparatus with reference to the head of the welding apparatus W.

Considering the chuck apparatus C in somewhat greater detail, a set of arcuate jaws 34 (FIG. 3) define a cylindrical configuration 36 (FIG. 2) which clampingly receives a valve V by mating engagement at the periphery of the head 10. As disclosed, three jaws 34 are provided, comprising copper (or other high chill material) each extending through an angle of 120. Upon closure of the jaws 34, the spaces 38 therebetween are closed to provide minimal space therebetween.

In the exemplary machine, the jaws 34 are supported by arms 40 (FIG. 3) that are affixed to extend radially from the external curved surface of each of thejaws The arms 40 are slidingly received in slots 42 which extend radially through a cylindrical support block 44. Springs 46 are affixed between the internal surface of the support block 44 and each of the jaws 34, thereby urging the jaws outwardly to an open configuration.

Movement of the jaws 34 inwardly, to a closed configuration, is accomplished by a ring 48 (FIG. 1) movable in a reciprocating vertical pattern to engage the inclined end surfaces 50 of the arms (FIG. 3) and thereby close the jaws 34. The ring 48, as indicated above, is mechanically coupled to the chuck actuating drive 26 so as to be raised and lowered. Recapitulating, when the ring 48 is raised, the jaws 34 are opened (under the force of the springs 46) toreceive a valve. Lowering the ring 48 closes the jaws 34, for mating engagement with the periphery of the valve. It is to be noted, that the valve' V is matingly engaged at the periphery 52 (FIG. 2) as well as along the edge of the bottom surface 53 of the head 10 by an annular shoulder 54. i

. The entire chuck apparatus C (FIG. 1) is mounted for rotation in the platform 24 on a rotary support 55,

as on hearings or the like (not shown) to facilitate movement by the rotary drive 28'. The chuck apparatus C accordingly rotates the valve V in relation to the welding apparatus W for the deposition of the metal annulus 18. In the illustrative embodiment, the welding apparatus W is a TIG (tungsten arc-inert-gas) apparatus. Accordingly, a nonconsumable electrode 55 is positioned adjacent to the chuck apparatus C along with a wire nozzle 56 for supplying tiller wire 58 to the valve V. The wire nozzle 56 receives filler wire from a spool 60 under control of a feed apparatus 62. The feed apparatus 62 incorporates an electric wire-feed motor (not shown) as well known in the prior art. The nonconsumable electrode 55 is connected to a power supply 64 for supplying electrical current to maintain the arc. The power supply is also connected to the chuck apparatus C through a conductor 66 and theplatform 24 to accommodate grounding current. The feed motor (not shown) or other wire drive, in the feed apparatus 62 is connected to a control unit 68 which is also connected to the power supply 64, the chuck drive 26, and the rotary drive 28.

In the operation of the system as depicted in FIG. 1, a variety of specific control structures may be employed to accomplish a sequence of operation, which will now be described. Initially, the control unit 68 may have the various operating components in a quiescent state. Specifically, the chuck drive 26 is inoperative with the result that the jaws 34 are open (spaced apart). Furthermore, the feed apparatus 62 is not moving wire nor is the power supply providing electrical current to the electrode 55. Finally, the rotary drive 28 is at standstill so that the chuck apparatus C also is stationary.

With the components in quiescent states, a valve V is positioned for engagement with the chuck C. The positioning of the valve V may be automated or, of course manual. When the valve V is appropriately positioned, the control unit 68 actuates the chuck drive 26 to lower the ring 48 closing the jaws on the valve V in a positional arrangement as depicted in FIG. 2. Next, the control unit 68 actuates the rotary drive 28 to turn the chuck apparatus C at a substantially constant rate of rotation. Thereafter, the control unit 68 concurrently energizes the power supply 64-and the feed apparatus 62. As a consequence, an arc is establishedbetween the tip of the electrode and the valve V while filler wire 58 is continuously supplied to the are.

As the valve V revolves, hard metal is deposited in the annular groove 16 (FIG. 6a) as explained above.

During the application of the hard metal, it is important to recognize that the grounding path for electrical current through the valve V is very short and extends essentially directly under the arc into the configuration 36 (FIG. 1). That is, the short path as indicated by the arrow 70 (FIG. 2) extending from the groove 16 to the cylindrical configuration 36 is representative of one path in a locus of paths about the valve V. I-Ieat flow from the arc follows a somewhat similar path with the result that temperatures developed within the .valve V remain well below critical levels.

Upon completion of a revolution (360 rotation) by the chuck apparatus C (FIG. 1) the control apparatus 68 halts the wire feed apparatus 62. Concurrently, the control unit 68 controls the power supply 64 to provide a reduced arc current so that the arc puddle becomes progressively smaller in the overlapped section thereby tapering in the pattern 22 (FIG. 5) as described above to eliminate a junction or shrinkage defects. After a rotation of a substantialoverlap, e .g. between 5 and 20, the arc current is reducedto a level at which the arc is no longer sustained and accordingly is extinguished.-

Thereafter, the rotary drive 28 is deenergized by the control unit 68 which then controls the chuck drive 26 to open the jaws 34. At that time, the valve V is released and is, accordingly, removed from the apparatus.

To complete the seating surface 14 (FIG. the annulus 18 is smoothed or trimmed to provide the desired uniform tapered surface '14. Accordingly, a valve is complete in a construction that will have an effective and prolonged life. Discontinuities are slight, if existent, and a uniform deposit is accomplished.

In general, it is important to recognize the significance herein of the manner in which a valve is supported during the application of hard metal. Specifically, the valve must be supported in such fashion as to provide effective heat transfer from the valve, a desirable grounding current flow pattern and a stable motion pattern with reference to the arc welding apparatus. Of course, within the purview of such considerations, a wide variety of various component structures are available. Consequently, the scope hereof shall be in accordance with the claims as set forth in detail below.

What is claimed is:

l. A system for producing a valve, as for an internalcombustion engine, which valve includes a disk section, the periphery of which abuts an annular seating surface, comprising:

a chuck means for receiving said valve and defining a closure-to matingly engage said periphery of said valve;

an arc welding means for depositing metal, and including a circuit connected through said chuck means; and

means for revolving said chuck means in relation to said welding means during an operating interval of said arc welding means to deposit an annulus of metal at said seating surface.

2. A system according to claim 1 wherein said chuck means includes a plurality of separable segments mating to define substantially complete contact with said periphery of said valve on closure.

3. A system according to claim 2 wherein said chuck means comprises copper.

4. A system according to claim 2 wherein said chuck means defines an annular shoulder for abuttingly engaging the flat surface of the disk section of said valve.

5. A system according to claim 2 wherein said chuck means includes an actuator means for concurrently moving said segmentsin radial directions.

6. A system according to claim 2 wherein said means for revolving comprises a rotary drive unit to turn said chuck means through a motion pattern of between one revolution and two revolutions.

7. A method of producing a valve, as for use in an internal-combustion engine, comprising the steps of:

providing a valve form including a stem and a head,

said head defining an annular groove at the periphery thereof;

supporting said valve form by matingly engaging said head at the periphery thereof, to provide effective electrical contact about said periphery; establishing an arc-welding current path through an electrode and said valve form, as supported; employing said current path to deposit an annulus of metal on said annular groove; and

finishing said valve including smoothing said annulus of deposited metal.

8. A method according to claim 7 wherein said valve is rotated about the central axis thereof during the deposition of said annulus of metal.

9. A method according to claim 8 wherein said annulus of metal is provided by rotating said valve through an angle of more than a single revolution whereby to diminish the weld puddle size progressively on completion of said single revolution.

10. A method according to claim 8 wherein said annulus of metal is provided by an overlapping, annular arc welding pattern and whereby said annulus is terminated by a decreasing current through an angle of several degrees. 

1. A system for producing a valve, as for an internal-combustion engine, which valve includes a disk section, the periphery of which abuts an annular seating surface, comprising: a chuck means for receiving said valve and defining a closure to matingly engage said periphery of said valve; an arc welding means foR depositing metal, and including a circuit connected through said chuck means; and means for revolving said chuck means in relation to said welding means during an operating interval of said arc welding means to deposit an annulus of metal at said seating surface.
 2. A system according to claim 1 wherein said chuck means includes a plurality of separable segments mating to define substantially complete contact with said periphery of said valve on closure.
 3. A system according to claim 2 wherein said chuck means comprises copper.
 4. A system according to claim 2 wherein said chuck means defines an annular shoulder for abuttingly engaging the flat surface of the disk section of said valve.
 5. A system according to claim 2 wherein said chuck means includes an actuator means for concurrently moving said segments in radial directions.
 6. A system according to claim 2 wherein said means for revolving comprises a rotary drive unit to turn said chuck means through a motion pattern of between one revolution and two revolutions.
 7. A method of producing a valve, as for use in an internal-combustion engine, comprising the steps of: providing a valve form including a stem and a head, said head defining an annular groove at the periphery thereof; supporting said valve form by matingly engaging said head at the periphery thereof, to provide effective electrical contact about said periphery; establishing an arc-welding current path through an electrode and said valve form, as supported; employing said current path to deposit an annulus of metal on said annular groove; and finishing said valve including smoothing said annulus of deposited metal.
 8. A method according to claim 7 wherein said valve is rotated about the central axis thereof during the deposition of said annulus of metal.
 9. A method according to claim 8 wherein said annulus of metal is provided by rotating said valve through an angle of more than a single revolution whereby to diminish the weld puddle size progressively on completion of said single revolution.
 10. A method according to claim 8 wherein said annulus of metal is provided by an overlapping, annular arc welding pattern and whereby said annulus is terminated by a decreasing current through an angle of several degrees. 